A presice understanding of the neurochemistry of PCP-induced violence, or for that matter, of violent behavior, itself, is lacking today. Without this understanding it is difficult to know how to specifically treat this behavior either after it has developed from drug use or prophylactically before it may develop in the case of the non drug-induced state. The objective of the present research is to gain a more precise understanding of the neurochemistry of both drug-induced an non drug-induced violent behavior. The specific aims of this proposal are to examine 1 - the relationship of dopamine autoreceptor subsensitivity and dopamine release to the development of fighting behavior using the isolated mouse model and the ability of PCP to interact with these parameters. Release will be studied both by the in vitro slice technique and in vivo by measuring DOPA accumulation after decarboxylase inhibition both in the presence and absence of PCP, and 2 - whether animals that are prone to violent behavior (fighting) exhibit altered PCP binding kinetics. Association and dissociation kinetics, KD and Bmax will be determined using membrane preparations derived from various areas of the brain. In every case, isolated fighting mice will be compared to non-fighting isolates and group-housed animals. To examine the relationship of the above parameters to the development of fighting, animals will be isolated 1, 2, 3, 4, 5-6 weeks. The time course of change in the neurochemistry will be compared to the time course of change in the behavior with weeks of individual housing to determine whether any correlation exists.